Drag bucket dumping apparatus



Aug. 5, 1958 P. L. clAcclo 2,346,100

DRAG BUCKET DUMPING APPARATUS Filed April 1, 1957 l 4 Sheets-Sheet 1 Immvron PETER L. Cmcc'lo 1 1a. 1 W

Aug. 5, 1958 I P. L, c|Acc|O 2,846,100

' DRAG BUCKET DUMPING APPARATUS Filed April 1, 195'! 4 Sheets- Sheet 224- FIG. 4 F162. 5 25 FIG. 2

H I a i z3 l JNVENTOR. 40 PETER L. ClAcclo gym 7 1958 P. L. CIACCIO V2,846,100

DRAG BUCKET DUMPING APPARATUS 4 Sheets-Sheet 3 Filed April 1, 1957INVENTOR. PE TEP L. Cm c010 1 "BEN E Y- Aug.- 5, 1958 P. L. CIACCIO2,846,100

DRAG BUCKET DUMPING APPARATUS Filed April 1. 1957 Shee1isSheet 4INVENTOR. .PETEE L Gmcclo 79TTORIYEV- United States PatentO DRAG BUCKETDUMPING APPARATUS Peter Ciaccio, West Los Angeles, Calif., assignor toFle ible Manufacturing Corporation, 'Los Augeles, Calm, a corporation ofCalifornia Application April 1, 1957, Serial No. 649,811 7 Claims. (Cl.214-712) This application is in part a continuation of my priorapplication S. N. 565,562, filed February 15, 1956, for Drag BucketDumping Apparatus.

This invention relates to sewer cleaning machines of the drag buckettype wherein portable derricks are set adjacent consecutive manholes ina sewer line to be leaned, and wherein a drag bucket is introduced intothe sewer line through one of the manholes, is advanced into and thendrawn back through the section of the sewer line between the manholeswith a dredging action, and is then hoisted through the manhole; swungto one side and dumped. The general object of the invention is toprovide in such an apparatus, a hoist having improved mechanism foreffecting the lateral shifting and dumping of the bucket.

In a drag bucket apparatus now in common use, the derrick is providedwith an unloading swing boom to which the loaded bucket is hitched as itis elevated from the manhole, and which is then swung horizontally abouta vertical axis to convey the bucket to position from which it can bedumped. Manual effort is required for swinging the loaded boom and fordumping the bucket at the end of its swing.

A primary object of the present invention is to substantially eliminatethe need for such manual eflort and to attain the horizontal swingingaction and dumping in a semi-automatic operation.

An important further object is to enable the execution of the entirebucket unloading operation much more rapidly than has hitherto beenpossible, thereby substantially increasing the daily work output of theapparatus.

Another object, a contributing factor to the attainment of the morerapid operation referred to above, is to provide a mechanism which willguide the movements of the bucket in the swinging and dumpingoperations, largely eliminating the necessity for hand guiding, andcorrespondingly speeding up such operations.

An important feature of the invention is the provision of a boom whichswings in a vertical plane on a horizontal axis, starting at an elevatedposition above the manhole where it grasps the bucket as the latter isshifted horizontally from the manhole.

The dumping of a drag bucket is effected by spreading the clam-shelllips which, when held together, constitute the bottom of the bucket. Thelips are controlled by linkage which is hooked to the drag cable andconstitutes the draft connection between the cable and bucket. Thus thelips are held closed by cable tension applied through the linkage, andopen by gravity (under the weight of the contents of the bucket) whenthe cable tension is relaxed. This is a feature of existing dragbuckets, but in the apparatus embodying such buckets, it has alwaysrequired the exercise of some skill and the coordinated efforts of twomen to swing the bucket carrying boom laterally to the dumping positionWhile mainaining just sufficient tension on the cable to maintain thebucket lips closed without retarding the swinging operation. One of theobjects of the present invention is to eliminate the need 2,846,100Patented Aug. 5, 1958 for such coordinated effort and skill and toutilize the restraining pull of the cable to control thehorizontalswinging operation while automatically maintaining sufficient tension tohold the bucket lips closed :until the dumping position is reached.

Another object is to provide means for automatically clasping the bucketto the end of "the swinging boom as an incident of hoisting the bucketabove the man hole. Accessory to this object, the invention providesmeans for holding the boom in an elevated position-above the man hole,and provides at the swinging end of the boom, a grapple which, insuchelevated position of the boom, is positioned to automaticallyreceive theedgeiof the bucket as it is elevated.

Further objects of the invention will-become apparent in the ensuingspecification and appended drawings, wherein:

Fig. 1 is a perspective view of an unloading hoist mechanism embodyingthe invention;

Fig.2 is a fragmentary detail side view of the boom control mechanism;

Fig. 3 is a front elevational viewofthe same;

Fig. 4 is a detail sectional view of the boom suspending pivot;

Fig. 5 is a detail side view of the grapple unit in the position thereofin which it receives the upwardly moving bucket, a portion of thegrapple clevis being broken away to illustrate the jaw;

Fig. 6 is a side view of the grapple unit in the dumping position;

Fig. 7 is a transverse sectional-view of the grapple unit taken on theline 77 of Fig. 5. v

Fig. 8 is a transverse sectional view of the latch unit taken on theline 8-8 ofFig. 1, and

Fig. 9 shows a modified form of the latch.

Referring now to the drawings in detail, I have shown therein, as anexample of one form in which the invention may be embodied, a dragbucket hoist embodying a derrick (indicated generally by the referencecharacter A) able adjustable supporting legs 10for firmlysupporting thederrick on the paved surface adjacent the manhole; including a dragbucket B which, in its positionshown in Fig. 1 and with the derrickproperly supported as above stated, is centered directly overthe'manhole; including a swinging boom C for swinging the bucket'Bhorizontally to a dumping position at one side of themanhole, suchposition being indicated in dotted lines in 'Fig. 1; a grappleunit D forgrasping the bucket as it is hoisted out of the manhole and supportingthe bucket at the end of the boom C as the latter swings horizontally;and boom latching mechanism E which operates, in response to certainmovements of boom C to control other movements thereof, in asemi-automatic manner which'will be more fully explained hereinafter. Atthis time it may be'briefly noted that mechanism E latches the boom Cin'its bucket coupling position shown in full lines andsubsequentlyreleases it for downward and lateral swinging movement in response toupward movement imparted to the boom by bucket B.

A. DERRICK MECHANISM The derrick A includes the adjustablesupportingle'gs 10, a pair of uprights 11 which are rigidly secured tohorizontal chassis members 12 of the mobile supporting carriage and maybe braced thereto by diagonal braces 13; a crown arch unit 14 secured tothe upper ends of uprights-11 and including a crownbeam 15 and atransverse brace bar 15; an overhead roller 16 over which there istrained a drag cable 17 coming from a Windlass apparatus including afree spooling cable drum 18 and 3 thence extending downwardly at 17" tothe drag bucket B; and a back lash pulley assembly 19, all of aconventional construction and arrangement as utilized, for example, inthe power bucket machines illustrated in the catalog of FlexibleSewer-Rod Equipment Co., of Los Angeles, California.

In the present invention, there is added to the derrick A a crane arm 21secured, as by a clamp 22, to crown beam 15, and braced by a truss 21'.its outer end is a depending bracket 23 which has a bifurcated lower end24 (Fig. 4) in which is mounted a pivot bolt 25. An elongated clevis 26,comprising a pair of bars 27 joined in spaced relation by end blocks 28(Figs. 2 and 4), 28, has its upper end received in the bifurcated lowerend 24 of bracket 23 and is pivotally suspended upon the pivot bolt 25which extends through the slot defined between bars 27.

It will now be apparent that arm 21, slide bracket 23 and pivot 25provide a vertically adjustable pivotal support for the upper end ofboom C at a position in front of and spaced horizontally from the planeof derrick supports 11, such that the boom C may normally assume aposition inclined downwardly and horizontally toward such supports toclasp the bucket B as it is hoisted out of the manhole. When releasedfor free swinging movement, boom C will swing by gravity under theweight of the loaded bucket, to the dumping position in which it extendsvertically downwardly as indicated in the dotted lines. Thus the lateralswinging of the boom supported bucket to its dumping position isenergized by the weight of the bucket and requires no manual effort.

B. THE DRAG BUCKET The drag bucket B is of conventional construction,embodying a cylindrical tubular body 31, a pair of clam shell type lips32 hinged at 33 to diametrically opposite sides thereof, and a pair ofoperator slides 34, each having a longitudinal slidable connection withbucket body 31, each having at its lower end a pair of pivotalconnections 35 to adjacent lateral corners of respective lips 32, andeach having at its upper end an aperture into which is pivotally hookedthe respective ends of a supporting bail 36, and at its lower end anaperture into which is pivotally hooked a lower bail 36, connected to acable section 17'. The terminal portions of the cable sections 17 and 17may be attached to bails 36, 36 by suitable connectors 37.

The above described bucket construction is in itself conventional, butis combined with other features of the present invention to provide thesemi-automatic operation which will be described more in detailhereinafter. It may be noted that in the operation of the bucket, theswinging of the bucket from above the manhole to its dumping positionmay be controlled by playing out the cable 17 while maintainingsufiicient restraining tension therein (transmitted to lips 32 throughslides 34) to maintain the lips 32 closed until the bucket reaches thedumping position, whereupon, by slackening the cable 17, the lips 32will swing downwardly around their pivots 33, drawing slides 34-downwardly. Thus opened, the bucket will discharge its contents and thecable 17 may then be rewound on drum 18 to draw the bucket back to theposition above the manhole, the renewed cable tension causing the lips32 to again close.

C. SWINGING BOOM Boom C comprises an arm 40 the upper end of which iswelded, at 40 (Fig. 2), to one of the bars 27 of clevis 26. Boom C alsoincludes a laterally projecting arm 41 arm 40 just below the upper endportion thereof that is secured to clevis 26. A coil spring 29,connected under I tension between the bend joining lateral arm 41 to itsend Secured to I portion 42, and the upper end of boom arm 40, normallymaintains the arm 41 in the position shown in Fig. 2 (with relation toarm 46) as determined by engagement of the short arm portion 42 againsta stop 30 that is welded to the upper end of arm 40.

Secured to the lower end of arm is a fiat end fitting 45 which supportsa pivot bolt 46 to which grapple D is pivoted.

Secured to clevis 26, as by welding, is a knuckle fitting 47 (Fig. 3) ofsleeve form, in which is mounted the shank 43 of a latch actuator wand49. Wand 49 is bent at an obtuse angle to its shank 48 (the latter beingnormal to the plane of boom members 40, 41, 42) and subtends an acuteangle to said boom plane, such that wand 49 may engage near the outerend of the latch control trigger lever hereinafter described. Wand 49projects generally toward the derrick A, and, in the raised, full lineposition of boom C, is inclined upwardly above the latching mechanism Eas shown in Fig. 1. As the boom C swings downwardly to the bucketdumping position, wand 49 correspondingly swings downwardly to theposition shown in dotted lines, wherein it engages and actuates thelatch mechanism E as hereinafter explained. Shank 48 is fixedly securedin knuckle fitting 47 by means of a set screw 50 which may be loosenedto adjust the angle between wand 49 and boom arm 41.

D. GRAPPLE UNIT Grapple unit D (Figs. 5 and 6) comprises a clevis 5iwhich embodies opposed fingers 52 and 53, the latter comprising a pairof flat, parallel cheeks that are spaced to provide a slot 54 forreceiving a pivoted gripping jaw 55. The cheeks are joined, at the lowerend of finger 53, by an integral web 56 which extends at an acute angle(in the range between 30 and 45) to the longitudinal axis of finger 53.Fingers 53 and 52 are integrally joined by a pair of bridges 57, formedas integral continuations of the cheek portions of finger 53, andsimilarly spaced. Bridges 57 are projected to provide a pair of spacedears which receive the fiat end fitting 45 of boom arm 40 and arepivotally connected thereto by the pivot bolt 46 extending throughregistering apertures in the bridge cars 57 and fitting 45.

Jaw is of segment shape, having a relatively wide end 58 of arcuatecontour and serrated to provide teeth 59 for gripping engagement withthe outer face of bucket body 3 The lower corner of arcuate end 58 ispivoted to finger 53 by a pivot bolt 66 extending therethrough andthrough registering apertures in cheek portions of finger 53. From pivot60, the arcuate array of teeth extends upwardly and around the pivotaxis with a continuously increasing radius, and in a path which may beapproximately spiral with reference to the pivot axis. The heel portionof arcuate end face 53, radially opposite pivot 60, in the open positionof the jaw shown in Pig. 5, is substantially tangent to the near side ofa slot that is defined between fingers 52, 53 and thus said heel portionis generally parallel to the opposite side of slot 61. The curvature ofend 5'3 is such that, as jaw 55 is tilted clockwise (as viewed in Figs.5 and 6) the point of tangency between arcuate end 58 and the line para:1 to the opposite side of slot 5]; will progressively so. upwardly.This point of tangency determines the center of pressure engagement ofteeth 59 against outer LAM / surface of the section of bucket body 31received in slot 61, with the inner surface of the bucket body engagedagainst the finger 52 at the opposite side of slot 6?, and may vary toaccommodate any variations in thickness of bucket bodies. The teeth 59are of saw-tooth form and are inclined upwardly to attain maximumpenetration of bucket body 31 in response to the downward pub of thebucket body under the weight of its cont'.. t:. whereby the grasp of thebucket by the grapple is anti matically tightened by the downward pullof the bucket. A major factor in the automatic tightening of the grapple'5 on the bucket, 'however, is the actuator linkage-which will now bedescribed.

The endof jaw-55'opposite arcuate end 58, which may be tapered as shownand which functionsas a lever,'is provided with an aperture in which ishooked a transverse trunnion end portion 62 of a link 63, thusprovidinga pivotal connection. Link 63 extends upwardly and is pivotallyconnected -by-means of a transverse trunnion end portion64-thereof, inan opening in an car at one end of a clamp 65 which is clamped, by meansof a clamping bolt66, upon boom arm 40 above fitting 4-5. Pivots 46, 60,62. and 64 are arranged in trapezoidal array'such'that when grappleclevis 51 is movedon-its pivot26, asindicated by arrow'67, in thedirection of alignment with boom arm 40, the consequent elongation inthe distance betweenpivots60 and 64 will result in the above mentionedclockwise pivotal movement of jaw 55 about its pivot 60, transmittedthereto by'link'63, with the result that teeth 59 will advance into slot61 and will grip the wall of the bucket body 31 previously looselyreceived by the grapple.

The above mentioned movement of grapple clevis 61 relative to boom arm40, in the aligning direction 55, results automatically from the actionof bucket B, in response to gravity, tending to maintain a dependingposition with its major axis vertical, as opposed to the action ofclevis 51 in tilting the bucket toward the inclined position shown indotted lines in Fig. 1, as the boom C swings from the coupling positionshown in full lines toward the-unloading position shown in dotted lines.It will-now be apparent that, in this swinging movement of the bucket ascoupled to the boom, a tilting couple will be applied to grapple clevis51 by the bucket, tending to widen'the angle between the longitudinalaxes of arm 40 and clevis 51 toward an alignment position, and the forceof this couple, which is resolved into clamping pressure ofteeth 59against the bucket body 31, will continuously increase to a maximum atthe end of the swing. This is important for the reason that, when thebucket reachesthe unloading position, the cable 17 is relaxed so.astopermit the slide bars 34 to shift downwardly and the clam lips 32to swing outwardly for discharging the contents of the bucket. Duringthis unloading of the bucket, the -full weight of the bucket issupported by grapple unit D. Conversely, as the bucket is drawn back tothe coupling position, under the pull of cable .17 as itis rewound onthe drum 18, the grip of jaws 55 against the bucket body 31 willgradually relax until, inthe position of boom C shown in full lines ofFig. 1, the bucket, still received in clevis 51 and hanging vertically,will-have tilted the clevis 51 in a counterclockwise direction as viewedin Fig. 5, so as to restore it to its original angularity with referenceto the boom 40, thus actuating the jaw 55 through linkage 53 to releaseits-grip on bucket body 31.

E. LATCHING MECHANISM As previously noted, latching mechanism Efunctions to normally latch boom C in the raised, coupling positionuntil the bucket is hoisted and coupled to grapple unit D, and thereuponoperates to release the boom C for downward and lateral swingingmovement, guiding the bucket to the dumping position.

To this end, latching mechanism E (Fig. 8) comprises a jaw 70 includinga bracket part 71 attached to the underside of crane arm 21, andincluding an integral arm 72 projecting downwardly and terminating in aguide finger 73 extending diagonally downwardly and outwardly from alatching space 74 that is defined between the inner margin of arm 72 anda pivoted jaw (latching hook) which is indicated generally at 75. Hook75 includes an elbow portion 76, hung on a pivot '77 mounted in bracketarm 72, an arm 78 integral with elbow portion 76 and projectingdownwardly parallel to arm 72 when thehook 75 is in a closedpositiomandahead 79 integral' with the lowerendof arm 78,-defin ing a supportingshoulder-80-as-the-lower extremity of latching space 74 and having aninner margin extending diagonally downwardly'an'd'outwardly in'opposedrelation to guide finger 73, so as to'define therewith a V- shapednotch. This 'notchfunctions toreceive the boom arm 41 as the latterswings upwardly'in' the swinging movement-of'boom"40toward the derrickA, and to guide the arm 41 upwardly into the latchingspace 74, the hookbeing forced laterallyin this movement'so as to open a gap throughwhichthe arm41 can pass. The shock of contact of boom arm 41 againstguide finger 73 and latch hook 75 in such upward swingingmovementiscushioned by-yielding actionof spring 29. As soon as the arm 41 hasclearedthesupportingshoulder-Silya tension spring 81, connected'betweenthe bracket arm 72 and the elbow 760f hook'75"and exerting a pullbelowthe pivot 77, will returnthe hook 75 to the closed'posi tion shown, inwhich it is arrested by contact ofthe lateral extremity of head '79against'finger-73.

The boom'C-is thus latched'in its normal position shown in full lines in.Fig. 1, and by slightly raising bucket B to remove itsweight fromgrapple D, it can be released from thegrapple and lowered into the sewerfor a new cycle of cleaning operation.

When the bucket has been filled andhoistedout of the sewer, it willreturn to the position shown in full lines in Fig. 1, in which its sideis about to enter the grapple-D.

Further upward movement of'the bucket will be transferred toboom C andto boom arm '41, which'wi1l engage against elbow 76 and willforce=thehook 75 upwardly to the dotted line position shown in Fig; 8,in'which position the hook will be held by'the action of spring 81exerting a pull above-the-pivot77, the arm 78 projecting laterallybeneath the latchactuator wand-'49 which has been elevated in unisonwiththe elevating'movement of boom arm 41. movement of boom arm 41, wand49 will swingdownwardly, engaging hook 75 and pushingit downwardly untilspring 81 has passed dead center, whereupon'the hook 75 will snap backto the-closed'positionshown in full lines, boom arm 41 meanwhile havingbeen unlatched and allowed to swing-downwardly to'its position shown inFig. 1.

OPERATION The operations of the various units of the mechanism have beendescribed in connection with the description of parts of such units andtheir relationship, and reference is made to the foregoing description.for detailed aspects of the functioning of the separate units. Thepresent explanation therefore aims to correlate the operation of thevarious units into a unified whole.

In the drag bucket cleaning of an underground sewer line, duplicateportable cable operating machines (hoists) are installed at difierentmanholes along the sewerline, the two hoists facing one another, thecable 17, 17 extending downwardly through one manhole, around suitableguide pulleys at the. bottom thereof, thence horizontally through thesewer line and thence upwardly around similar guide pulleys and outthrough the other manhole. Bail'36, hooked to the upper end of bucket B,is opposed to bail 36' which is hookedto the lower endsof slide bars 34and is attached to the other section 17' of the cable. This othersection17 has its remote end wound upon the drum 18 of the machine which isremote from the one shown in Fig. 1. Assuming that the bucket B as shownin Fig. 1 has just .been released by grapple unit D, the remote machinewill be operated to tension cable section 17' and draw the bucketdownwardly into the near manhole (this action positively opening thelips 32) and the bucketis then drawn lengthwise thro'ughthe sewer lineso as todredge .accumulated dirt and debris therefrom.

The cable 'section17' shown in'Fig. 1 is played out Upon subsequentdownward swinging during this movement. At a proper point, as judged bythe experience of the operator, the movement is reversed, cable section17 being wound upon drum 18 of Fig. l, and the other cable section 17'being relaxed and allowed to follow while the bucket is returned to thenear manhole, completing the filling of the bucket, and the bucket isthen hoisted through the manhole and returned to the coupling positionshown in Fig. 1. This reversal of movement will have closed lips 32 atthe beginning of the return movement of the bucket, and the lips willremain closed as the bucket is hoisted to the coupling position.

With the boom arm 41 latched in raised position as shown in Fig. 1,grapple unit D will be disposed in the proper position to receive theupper end portion of bucket body 31. The edge of the bucket is guidedinto slot 61 by the inclined lips 69 of fingers 52, 53 and rises in slot61 until it engages the upper end thereof. The bucket is then lifted afurther distance sufficient to swing boom C upwardly to the point whereboom arm 41 has engaged latch hook elbow 76 and shifted the latch hook75 upwardly to the unlatching position shown in dotted lines of Fig. 7.The operator then plays out the cable section 17 so as to allow thebucket and boom C to swing downwardly in unison, sufficient restrainingpull on the cable 17 being maintained to hold the bucket against theupper end of the grapple slot 61. Actually, it is only necessary torestrain the cable sufiiciently to avoid development of slack therein asthe bucket and boom swing downwardly, and thus it is possible to allow asubstantially free swing and to take advantage of momentum in carryingthe bucket to a maximum distance horizontally from the manhole. As theswing progresses, the bucket will be forced by grapple D to tiltupwardly from its originally vertical position to substantially matchthe angular shifting of boom C, but the gravity resistance of the bucketto being thus tipped upwardly will cause the grapple clevis 51 to shiftsomewhat toward a position of alignment with arm 46 (e. g. from startingposition shown in Fig. to the shifted position shown in Fig. 6) therebyactuating the jaw 55 to securely grip the bucket body as the swingprogresses.

At the end of the swing, with the boom C in a substantially dependingposition as indicated in dotted lines in Fig. 1, the cable section 17 isrelaxed to the point where the weight of lips 32 under the bucketcontents, assisted by the weight of the slide bars 34 and parts 36 and37, will shift slide bars 34 downwardly and lips 32 will swing to theiropen positions, discharging the contents of the bucket at one side ofthe manhole.

As the boom C swings downwardly, actuator wand 49 will correspondinglyswing downwardly until it contacts hook 75 as indicated in dotted linesin Fig. 7, and will continue its downward movement, pressing the hook 75downwardly until the spring 81 passes dead center and becomes operativeto snap the hook to its closed position. Thus the latch mechanism isreset for a subsequent latching operation.

At the end of the unloading operation, the machine is operated to windcable section 17 on drum 18, drawing the bucket B back toward derrick A,the boom C following, until the parts return to the position in whichthe bucket was initially coupled to grapple D. In the final stage ofthis movement, boom arm 41, entering the notch between head 79 and guidefinger 73, will engage and shift the hook 75 laterally until it clearsthe shoulder 80, whereupon the hook 75 will be spring returned to theclosed position, thus latching the boom in the coupling position. Inreturning to this position, the bucket B, assuming a verticallydepending position by the operation of gravity, shifts the grappleclevis S1, with reference to arm 40, in a clockwise direction as viewedin Figs. 4 and 5, restoring it substantially to the position shown inFig. 5 in which jaw 55 has been actuated by link 63 to release its gripon bucket body 31.

The bucket A may now be lowered, leaving'the grapple D suspended in thecoupling position in which it is again engaged by the bucket when thelatter is drawn from the manhole with another load therein. The bucketis now lowered into the manhole to receive the subsequent load ofmaterial, thus completing the cycle of operation.

The operation is particularly characterized by the fact that the entirecycle of operation of the apparatus can be controlled by operatorsoperating the two sections of the cable in unison so as to alternatelydraw the bucket into the sewer line, then return it to the hoistedcoupling position, then move it through the various stages of unloading,and then return it to the sewer without touching the bucket.

The modified latch of Fig. 9

The bracket and pivoted hook may be conveniently referred to as a pairof jaws between which the arm 41 is latched. Either one or both of thesejaws may be provided with a supporting shoulder or shoulderscorresponding to the shoulder of Fig. 1. By way of example of analternate construction that may be utilized, Fig. 9 illustrates amodified latch arrangement wherein fixed jaw 79a includes a downwardlyextending arm 72a having an integral head 73a defining a supportingshoulder 80a which projects laterally from the inner margin of arm 72atoward the pivoted jaw 75a. Jaw 75a includes an elbow portion 76a, adownwardly projecting arm 78a and a guide finger 79a, arranged inlaterally opposed, downwardly diverging relation to head 73a. In thisarrangement, the latch is so positioned with reference to the plane ofnormal vertical swinging movement of arm 41, (which plane as well as thevertical free movement of arm 41 is indicated by the broken arrow a)that the arm 41 would just clear the extremity of shoulder 86a if thejaw 75a were absent. There is sufficient torsional flexibility in theassembly of boom C and its mounting, in the pivotal connection of arm 41to the boom arm 4!] and in the arm itself, so that the jaw 75a, underthe pull of jaw closing spring 81a, will deflect the arm 41 laterallyinto the latching space 74a after the arm 41 has cleared the shoulder80a in its upward movement. In such upward movement, arm 41 will firstcontact guide finger 79a in the full line position shown, will bedeflected slightly toward guide finger 73a by camming engagement withfinger 79a, until it engages finger 73a just below the extremity ofshoulder 80a, and will then ride against the inclined margin of finger73a diagonally upwardly, shifting jaw 75:: away from jaw 70a until itclears the extremity of shoulder 80a, and then, being sufiiciently closeto spring 81a so that the closing force exerted by the spring throughjaw arm 78a will be sutficient to deflect it into its latched positionshown in dotted lines, the arm 41 will shift over to that position whereit will be supported by the shoulder 80a.

in the further upward movement of arm 41, it will engage spring 18,which will yield upwardly, and arm 41 will then engage elbow 76a in amanner similarly to the operation of the previously described latch ofFigs. 1 and 7, will shift the jaw 75a upwardly to the open positionshown in dotted lines, with the spring 81a crossing over center to holdit in this position, and, thus freed from the restraining pressure ofjaw 75a, arm 41 will move laterally as indicated by arrow 85b to resumea position in its plane of normal free swinging movement in line withbroken arrow 85a, in which it will clear the outer extremity of shoulder80a for unrestrained downward movement when the boom is allowed to swingaway from the derrick to the dumping position. During such downwardswinging movement of the boom assembly, the jaw 75a will be engaged bythe wand 49 and returned to its closed position shown in full lines.

I claim:

1. Apparatus for unloading a cable-suspended drag bucket having-anopenablebottom maintained closed by cable tension, comprising: a derrickhaving atits upper end means for suspending a length of cable forhoisting sai'd bucket from a filling position; a crane arm secured tosaid upper end of the derrick and projecting horizontally; a grappleadaptedto receive and to grasp an upper edgeof said zbucket; a boomhaving a free lower end carrying said grapple and a pivot suspending itsupper end from said crane arm for lateral swinging movement in responseto gravity acting upon said bucket, from a coupling position to anunloading position, said boom in the coupling position being inclinedlaterally from the vertical with said grapple elevated in position toreceive said upper edge portion of the bucket as the latter is hoistedfrom said filling position, and in said unloading position said boomhanging freely from its saidpivot-and said grapple being disposeddownwardly from said elevated position; a lateral arm attached to andprojecting laterally from said boom; latch mechanism for supporting saidboom in said coupling position, comprising a jaw attached to theunderside of said crane arm and projecting downwardly and terminating ina guide finger that is downwardly and laterally inclined, a latchinghook pivoted to said jaw and provided at its free end with a head havinga downwardly and outwardly inclined inner margin cooperating with saidguide finger to define an upwardly narrowing notch to receive saidlateral arm of the boom as the latter swings toward its couplingposition, said head having a latching shoulder adapted to support saidlateral arm in the coupling position of the boom, spring means operatingbetween said hook and said jaw to normally maintain said hook in aclosed position in which said lateral arm may be supported on saidlatching shoulder, said spring means being also operable to yieldinglysupport said hook in an open position projecting laterally from said jawand releasing said lateral arm for downward swinging movement of theboom; and an actuator wand attached to the boom and moving in a pathabove said hook, intersecting the open position thereof as the boomswings downwardly and engaging the hook to return it to its closedposition.

2. Apparatus for unloading a cable-suspended drag bucket having anopenable bottom maintained closed by cable tension, comprising: aderrick having at its upper end means for suspending a length of cablefor hoisting said bucket from a filling position; a grapple adapted toreceive and to grasp an upper edge of said bucket; a. boom having a freelower end carrying said grappleand a pivot suspending its upper end fromsaid derrick for lateral swinging movement in response to gravity actingupon said bucket, from a coupling position to an un loading position,sm'd boom in the coupling position being inclined laterally from thevertical with said grapple elevated in position to receive said upperedge portion of the-bucket as the latter is hoisted from said fillingposition, and in said unloading position'said boom hanging freely fromits said pivot and said grapple being disposed downwardly from saidelevated position; a lateral arm attached to and projectinglaterally'from said boom; latchmechanism for supporting said boom insaid coupling'position, comprising a jaw secured to the derrick,projecting downwardly and terminating in a guide finger that isdownwardly and laterally inclined, a latching hook pivoted to said jawand provided at its free end with a head having an inner margincooperating with said guide finger to define an upwardly narrowing notchto receive said lateral arm of the boom as the latter swings toward itscoupling position, said head defining a latching shoulder, spring meansoperating between said hook and .said jaw to'normally maintain said hookin a closed position in which said latching shoulder faces upwardly forsupporting said lateral arm and in which said head engages said jaw'toprovide, above said shoulder and between saidjaws, a space for receivingsaid lateral arm' with said arm'confined-between said hook and jawirisu'p ported relation, saidlatching hook having aportionthere" ofwhich, in the said closed position of the hook,ispositioned to beengaged-by said lateral arm'duringfurth'er upwardmovementthereof,whereby said hook willbe' swung upwardly to an openposition-projectinglatera'll'y' from said jaw and-releasing saidlateral arm for down=' wardswinging movement of the boom, said spring'mean's being operable toyielding'ly support'said hook in said open position; and anactuator'wand attached'to'the boom and moving in apath above saidhook,intersect ing the openposition'thereof' asthe boom swings down wardlyand engaging the'hook to return it toits'closed" position.

3. Apparatus for unloading a cable-suspended tdrag bucket having anopenable bottom maintained 'close'dby' cable tension, comprising: aderrick'having atits upper end means for suspending a length ofcable.for"hoisting' said bucket from a'filling position; a grappleadapted to receive and to grasp an upper'edge of said bucket; a. boomhaving a free lower end carrying said grapple and. a pivot suspendingits upper endfrom said derrick for lateral swinging movement in responseto gravity acting:

upon said'bucket, from a coupling position tolan unload-- ing position,said boom in the coupling position being iii-- clined laterally'from thevertical with said grapple ele-- vated in position to receive said upperedge portion of the bucket as the latter'is hoisted from said fillingposition,-v

and'in said unloading position said boom hanging freely from its saidpivot and said grapple being disposed down wardly from said elevatedposition; a lateral arm .at-"

tachedto and projecting laterally from said boom;'latch: mechanism forsupporting'said boom in said coupling; position, omprising a jaw securedto said derrick and. projecting downwardly, a latching hook pivoted tosaid. jaw and provided at its free end with a headlhaving a1 downwardlyand outwardly inclined margin cooperating: with said jaw to define anupwardly narrowing notch toreceive said lateral arm of the boom as thelatter swings; toward its coupling position, said headdefininga latchingshoulder, spring'means'operating between saidhook' and said jaw tonormally maintain said hook in a closed position in which said latchingshould'erfaces upwardly'for supporting said lateral arm and in whichsaid head engages said jaw to provide, above said shoulder andibetweensaid jaws, a space for receiving said lateral arm with said arm confinedbetween the jaws in supported re-' lation, said latching hook havingtaportion thereof which, in the said closed position of the hook, ispositionedto be engaged by said lateral arm during further upwardmovement thereof, whereby said hook will be swung :upwardly to an'openposition projecting laterally fromlsaid jaw and releasing said lateralarmfor downward swinging movement of the boom, said spring means .beingoperable to yieldingly support said hook in said open positiomand anactuator wand attached to the' boom-and moving in'a path above saidhook, intersecting the'op'en' position thereof as the boom swingsdownwardly and:engaging the hook to return it to its closed position.

4. Apparatus for unloading a cable-suspended drag bucket having anopenable bottom maintained closed by cable tension, comprising: aderrick having atrits upper endmeans'for suspending a length of cableforhoisting said bucket from a filling position; agrapple adaptedtoreceive and to grasp an upper edge of said bucket; a boom having a freelower end carrying said grapple and a pivot suspending its upper endfrom said-derrick for lateral swinging movement in response to gravityacting upon said bucket, from a coupling position to an unload-. ingposition, said boom in the coupling position being'inclined laterallyfrom the vertical with said grapple elevated in position to receive saidupper edgeportion of the bucket as the latter ishoiste'd fromsaidifillingrposition, and in said unloading position said boomrhangingfreelyfrorn' its said pivot and said grapple being disposed downwardlyfrom said elevated position; a lateral arm attached to and projectinglaterally from said boom; latch mechanism for supporting said boom insaid coupling position, comprising a jaw attached to said derrick andprojecting downwardly, a latching hook including an elbow portionpivoted to said jaw, an arm projecting at an obtuse angle from saidelbow portion, and a head on the free end of said hook arm, said headdefining a latching shoulder, a coil spring operating under tensionbetween said hook and said jaw to normally maintain said hook in aclosed position in which said hook arm extends downwardly in laterallyspaced relation to said jaw and said shoulder faces upwardly to providea support for said lateral arm of the boom and cooperates with said jawand hook arm to define a latching space in which said lateral arm may bereceived, and said elbow portion, in said closed position of the hook,extending diagonally upwardly to its pivot and being engageable by saidlateral arm upon further upward movement thereof so as to effect upwardswinging movement of said hook to an open position in which said hookprojects laterally from said jaw and in which said spring is disposedabove said pivot so as to yieldingly support the hook in said openposition; and an actuator wand attached to the boom and moving in a pathabove said hook, intersecting the open position thereof as the boomswings downwardly and engaging the hook to return it to its closedposition.

5. Apparatus for unloading a cable-suspended drag bucket having anopenable bottom maintained closed by cable tension, comprising: aderrick having at its upper end means for suspending a length-of cablefor hoisting said bucket from a filling position; a grapple adapted toreceive and to grasp an upper edge of said bucket; a boom having a freelower end carrying said grapple and a pivot suspending its upper endfrom said derrick for lateral swinging movement in response to gravityacting upon said bucket, from a coupling position to an unloadingposition, said boom in the coupling position being inclined laterallyfrom the vertical with said grapple elevated in position to receive saidupper edge portion of the bucket as the latter is hoisted from saidfilling position, and in said unloading position said boom hangingfreely from its said pivot and said grapple being disposed downwardlyfrom said elevated position; a lateral arm attached to and projectinglaterally from said boom; latch mechanism for supporting said boom insaid coupling position, comprising a pair of jaws including a fixed jawattached to said derrick and projecting downwardly, and a swinging jawpivoted to said fixed jaw for swinging movement in a vertical plane, oneof said jaws being in the form of a hook having a head defining alatching shoulder, the other of said jaws having at its lower end aguide finger that has a downwardly and laterally inclined inner margin,said head likewise having a downwardly and laterally inclined innermargin, said inclined margins diverging downwardly to define an upwardlynarrowing notch to receive said lateral arm of the boom as the boomswings upwardly toward its coupling position, and a coil springoperating under tension between said jaws to normally maintain them inclosed positions in which said head of the one jaw engages the otherjaw, in which said shoulder faces upwardly, and in which said shoulderand the jaws define above said shoulder a latching space for receivingand supporting said lateral arm in the coupling position of the boom,said lateral arm being engageable with said pivoted jaw, upon upwardmovement above said shoulder, to swing said pivoted jaw upwardly to anopen position projecting laterally from said fixed jaw, to release theboom for downward swinging movement, said spring being arranged to moveover center to a position above the pivot of said swinging jaw when thelatter moves to said open position, so as to yieldingly support saidswinging jaw in said open position; and an actuator wand attached to theboom and moving in a path above said swinging jaw, intersecting 12 thelaterally projecting open position thereof as the boom swings downwardlyand engaging said swinging jaw to return it to its closed position.

6. Apparatus for unloading a cable-suspended drag bucket having anopenable bottom maintained closed by cable tension, comprising: aderrick having at its upper end means for suspending a length of cablefor hoisting said bucket from a filling position; a grapple adapted toreceive and to grasp an upper edge of said bucket; a boom having a freelower end carrying said grapple and a pivot suspending its upper endfrom said derrick for lateral swinging movement in response to gravityacting upon said bucket, from a coupling position to an unloadingposition, said boom in the coupling position being inclined laterallyfrom the vertical with said grapple elevated in position to receive saidupper edge portion of the bucket as the latter is hoisted from saidfilling position, and in said unloading position said boom hangingfreely from its said pivot and said grapple being disposed downwardlyfrom said elevated position; a lateral arm attached to and projectinglaterally from said boom; latch mechanism for supporting said boom insaid coupling position, comprising a pair of jaws including a fixed jawattached to said derrick and projecting downwardly, and a swinging jawpivoted to said fixed jaw for swinging movement in a vertical plane, oneof said jaws being in the form of a hook having a head defining alatching shoulder; said jaws having at their lower ends, inner marginsdiverging downwardly to define an upwardly narrowing notch to receivesaid lateral arm of the boom as the boom swings upwardly toward itscoupling position, and spring means operating between said jaws tonormally maintain them in closed positions in which said head of the onejaw engages the other jaw, in which said shoulder faces upwardly, and inwhich said shoulder and the jaws define above said shoulder a latchingspace for receiving and supporting said lateral arm in the couplingposition of the boom, said lateral arm being engageable with saidpivoted jaw, upon upward movement above said shoulder, to swing saidpivoted jaw upwardly to an open position projecting laterally from saidfixed jaw, to release the boom for downward swinging movement, saidspring means being arranged and operable upon said swinging jaw when thelatter moves to said open position, so as to yieldingly support saidswinging jaw in said open position; and an actuator wand attached to theboom and moving in a path above said swinging jaw, intersecting thelaterally projecting open position thereof as the boom swings downwardlyand engaging said swinging jaw to return it to its closed position.

7. Apparatus for unloading a cable-suspended drag bucket having anopenable bottom maintained closed by cable tension, comprising: aderrick having at its upper end means for suspending a length of cablefor hoisting said bucket from a filling position; a grapple adapted toreceive and to grasp an upper edge of said bucket; a boom having a freelower end carrying said grapple and a pivot suspending its upper endfrom said derrick for lateral swinging movement in response to gravityacting upon said bucket, from a coupling position to an unloadingposition, said boom in the coupling position being inclined laterallyfrom the vertical with said grapple elevated in position to receive saidupper edge portion of the bucket as the latter is hoisted from saidfilling position, and in said unloading position said boom hangingfreely from its said pivot and said grapple being disposed downwardlyfrom said elevated position; a lateral arm attached to and projectinglaterally from said boom; latch mechanism for supporting said boom insaid coupling position, comprising a fixed jaw attached to said derrickand projecting downwardly and terminating in a head defining an upwardlyfacing latching shoulder, a swinging jaw pivoted to said fixed jaw forswinging movement in a vertical plane between a closed position in whichit extends downwardly from its pivot and engages 13 said head to providea closed latching space above said shoulder, for receiving andsupporting on said shoulder the lateral arm of the boom, and an openposition in which it projects laterally from said fixed jaw to releasethe boom for downward swinging movement; said jaws having, below saidlatching shoulder, downwardly diverging opposed inner margins defining anotch for receiving said lateral arm and guiding it into said closedlatching space as it moves upwardly, and said swinging jaw beingarranged to be engaged by said lateral arm upon upward movement of thelatter beyond its latching position, to move said swinging jaw to saidopen position; and a coil spring operating under tension between saidjaws to normally maintain said swinging jaw in said closed position,

said spring moving over center to a position above the 15 pivot of theswinging jaw when the latter moves to said open position, for yieldinglysupporting the swinging jaw in its said open position; and an actuatorwand attached to the boom and moving in a path above said swinging jaw,intersecting the open position thereof as the boom swings downwardly andengaging the swinging jaw to return it to its closed position.

References Cited in the file of this patent UNITED STATES PATENTS1,234,717 Beindorff July 31, 1917 2,417,121 Nelson Mar. 11, 19472,502,593 Robinson et al. Apr. 4, 1950

